How does carrier testing identify people who may pass on a genetic disorder?

Carrier testing is a diagnostic process used to determine if an individual carries a genetic mutation that could be passed on to their children, even if the individual does not personally exhibit symptoms of the disorder. These tests are typically offered to individuals based on their family history or ethnic background, which may suggest an increased risk for specific inherited conditions.1

The identification of carriers relies on various laboratory techniques, primarily focusing on DNA analysis. Because DNA can be extracted from tiny tissue samples, scientists use methods such as polymerase chain reaction (PCR) or microarray hybridization to detect specific mutations, including point mutations or chromosomal rearrangements. In some cases, such as with sickle cell anemia, testing may involve analyzing protein products like hemoglobin when they are more accessible or cost-effective than DNA analysis.12

By identifying these mutations, carrier testing provides prospective parents with critical information for family planning. Genetic counselors often work with individuals to interpret these results, helping them understand the inheritance patterns—such as autosomal recessive or X-linked traits—and the associated risks for their future children.134